package 链表;

/**
 * @Author: LDeng
 * @Date: 2021-02-20 15:53
 * https://leetcode-cn.com/problems/linked-list-cycle/submissions/
 */
public class _141_环形链表 {

    public boolean hasCycle(ListNode head) {
        if(head==null || head.next==null){
            return false;
        }

        ListNode slow=head;
        ListNode fast=head.next;

        while(fast!=null && fast.next!=null){
            if(slow==fast){
                return true;
            }
            slow =slow.next;
            fast=fast.next.next;
        }
        return false;
    }

}
